A semiconductor device is commonly provided in a package as a packaged semiconductor device. The packaged semiconductor device usually has a plurality of pins, allowing to connect the packaged semiconductor device to other devices by, typically, soldering. The pins of the packaged semiconductor device are connected to pads of the semiconductor device with bonds, such as bond wires or bond bumps. A pin carrying a small signal is usually connected to a single pad with a single bond, as such single bond may easily carry the current of such a small signal. However, when large signals are involved, such as in a power driver circuit having a power transistor capable of providing a large current, multiple bonds are needed to carry the associated large current: a single pin is then usually connected with a plurality of bonds to a plurality of pads. This plurality of pads is then driven in parallel from the power transistor, whereby each pad and corresponding bonds carries a part of the large current. For example, for a 1 A power transistor, two bonds for carrying 500 mA each may be used, or even 10 bonds for carrying 100 mA each.
To allow proper functioning of the packaged semiconductor device initially and over its intended lifetime, it may be required that all bonds are correctly connected to the pin of the package and the pads of the semiconductor device. If for example for the 1 A power transistor with two bonds mentioned above, one of the bond wires would not be correctly connected, the other bond wire would have to conduct the full current of 1 A, whereby this other bond wire may fail after some time of operation because this other bond wire will be overstressed. Although a large majority of incorrectly connected bonds may be detected by testing the packaged semiconductor device immediately after the bonding has been performed during its manufacturing, a fraction of incorrectly connected bonds may pass such test. A packaged semiconductor device having such incorrectly connected bonds may be insufficiently reliable, as it may e.g. result in device failure after the packaged semiconductor device has been used for a prolonged period.
There is thus a wish to provide an improved packaged semiconductor device. There may be a wish to provide an improved method of testing whether all bonds are correctly connected in a packaged semiconductor device.